This invention is in the area of portable computers and pertains more specifically to small portable computing devices known in the art as personal digital assistants, and to Basic Input/Output Systems (BIOS) for such devices.
Personal Digital Assistant (PDA) units, as of the date of this disclosure, enjoy a position of hope in the computer marketplace. Some believe this approach, a small, relatively inexpensive, and eminently portable computer unit, having software specifically written for tasks a user might expect to perform while travelling, will provide eminently useful and therefore salable computer products. Apple Computer, Hewlett Packard, and several other well-known computer manufacturers have made a considerable investment at no small risk in such systems.
Given the new systems now introduced, and those coming, for what is now known about them, there are still a number of drawbacks and problems. For example:
1. The PDA systems introduced are relatively costly, with starting prices ranging from several hundred dollars to two thousand dollars and more. At such prices, rivalling current pricing for desktop systems, the buying public may react negatively. It is true that prices will fall with increased manufacturing volume and competition, but the high end start may well be rejected by potential users.
2. The systems being offered are still relatively bulky, considering the limited range of tasks that may be accomplished. Most are certainly too big to be conveniently carried in a breast pocket. The Newton, manufactured by Apple Corporation, weighs about a pound and is approximately the size of a VHS video cassette.
3. A big drawback of the PDA systems being offered is the way they transfer data between a user""s desktop unit, or other host, and the PDA. Known communication is by modem, by infrared communication, and by serial connection. These all require manipulation by a user, modulation on one or both ends of the communication path, and the like, which can be time-consuming, error-prone, and hardware extensive (expensive). Presently the Newton offers a modem and/or LED communication as an option, adding to the overall cost.
4. In known PDAs, software is typically recorded in ROM, so updating applications can be difficult, and sometimes impossible. This will be a problem because PDA users will not want the PDA to have the same capabilities at all times. Typical users will be people who travel and work while they travel. These users require different functions for a trip to Taiwan than for a trip to France, for example. What is needed is a quick and convenient means to update and substitute software.
5. Another difficulty is in the fact that the data files a user manipulates while travelling are typically data files also resident in a home unit, herein called a host unit, such as the user""s office desktop machine or notebook or other portable computer. It is very troublesome to have two or more sets of critical data, with differences that one must remember to correct at an appropriate time. This can cause unending grief if files are not correctly updated. At best, current PDAs must use a relatively slow compressed bus to download and upgrade files. Typically this is done through a serial port, using a linking application like Laplink(trademark).
6. Yet another difficulty with small devices like digital assistants is in providing embedded code routines, such as BIOS routines, in a minimum read-only memory (ROM) real estate. There is a considerable motivation to provide routines embedded in ROM, because ROM is relatively inexpensive, and always a requirement for minimum size and cost.
What is needed is a small and inexpensive PDA that has a range of features that eliminate the above-described risks and problems. This new unit needs to be smaller than those presently being introduced, such as about credit-card size, or perhaps modeled on the PCMCIA type II or type III standard form factors. It should be inexpensive enough to produce that at least a minimum version could be sold in the roughly $100-$200 range, so it will be a unit seen to be a relatively inexpensive necessity. A PDA unit of this sort is the subject of the present invention, and is termed by the inventors a micro-PDA, or xcexcPDA.
A very important feature of the xcexcPDA in an aspect of the present invention is a direct parallel bus interface with a connector allowing the unit to be docked by plugging it into a docking bay in a host unit. Moreover, when the xcexcPDA is docked in the host, there needs to be a means to effectively disable the CPU in the xcexcPDA and to provide direct access to both the xcexcPDA software and data storage by the host CPU. This direct access would provide immediate ability to communicate in the fastest available fashion between the xcexcPDA and the host, and would also facilitate additional important features to be described below.
The xcexcPDA also needs to have an optional compressed bus interface, including a connector separate from the host interface, so add-on devices may be utilized, such as a FAX modem, cellular communication, printer, and so on.
An additional feature that could be optionally provided in another aspect of the invention is an interface at the host to allow a user to select pre-arranged software mixes for loading to the xcexcPDA. This feature comprises a set of control routines operating in conjunction with the host""s display and input means, to allow the user to quickly select applications and perhaps data as well to be loaded to the xcexcPDA satellite, to configure the smaller, more portable unit for specific itineraries and purposes.
Another desirable feature is an ability to automatically update data files. In this aspect of the invention, with the xcexcPDA docked, data on the host, if carrying a later date and/or time stamp than the data on the xcexcPDA, would be automatically updated on the xcexcPDA and vice-versa. When one returns from an excursion using the xcexcPDA and docks the satellite at the host, the host gains access, determines the location of the latest files, and accomplishes the update. This feature needs to have some built-in user prompting to be most effective. It makes the xcexcPDA a true satellite system.
In addition to the above, it is also desirable that the xcexcPDA be served with code embedded in one or more ROM chips in a manner to allow more code to be provided than the apparent capacity of the ROM.
In a preferred embodiment of the invention a personal digital assistant module is provided comprising an enclosure for enclosing and supporting internal elements, a microcontroller within the enclosure for performing digital operations to manage functions of the personal digital assistant module, and a memory means connected to the microcontroller by a memory bus structure for storing data and executable routines. There is a power supply means within the enclosure for supplying power to functional elements of the personal digital assistant module, a display means operable by the microcontroller and implemented on a surface of the enclosure, and input means connected to the microcontroller for providing commands and data to the personal digital assistant module. A host interface means comprising a host interface bus structure, which may be configured as a PCMCIA bus interface, is connected to the microcontroller and to a first portion of a host interface connector at a surface of the enclosure, and the host interface means is configured to directly connect the microcontroller to a compatible bus structure of a host computer.
In an embodiment, the personal digital assistant module has a BIOS embedded in ROM in a compressed fashion, along with an uncompressed portion for testing and initializing system memory on start-up, and an uncompressed compression utility routine configured for decompressing the compressed BIOS portion.
In another embodiment the personal digital assistant module has an expansion bus interface comprising an expansion bus structure connected to the microcontroller and to a first portion of an expansion bus connector for connecting the microcontroller to a peripheral device. A wide variety of peripheral devices are provided for use with the personal digital assistant of the invention.
In another aspect, the personal digital assistant module also has a nonvolatile storage device, such as an EEPROM connected to the microcontroller and containing one or more codes unique to the personal digital assistant, for uniquely identifying the personal digital assistant to digital devices connected on the host interface.
In a preferred embodiment, the display and input means for the personal digital assistant are configured as an overlaid touch screen and LCD display on a surface of the outer case of the personal digital assistant. A pointer device implemented as a thumbwheel in one embodiment and as a pressure sensitive pad in another is provided as part of the input capability.
The personal digital assistant module forms a unique combination with a general-purpose computer host having the personal digital assistant as a satellite unit. The host in this instance has a docking bay especially configured to dock the personal digital assistant, making a direct bus connection between the local CPU of the personal digital assistant and the CPU of the host. The host may be a desktop unit, a notebook computer, or a smaller portable like a palmtop computer. This combination provides power and convenience not before available.
Many other digital devices are also provided according to various aspects of the invention, such as modems, scanners, data acquisition peripherals, cellular phones, and a software vending machine, and all of these devices may be appended to the personal digital assistant by the expansion bus interface or, in many cases, by the host interface.
The personal digital assistant provided according to embodiments of the present invention is a unit more compact than conventional PDAs. It represents a new dimension in computer application and applicability, in a form promising to be eminently usable by and useful to almost everyone; and at a price easily affordable. It solves the communication problem intrinsic to personal digital assistants relative to larger and more powerful computers, with a unit that fits into a user""s breast pocket, and at a very low price.